Dream control has been the stuff of Hollywood movies like “Inception” and “Dreamscape.” An iPhone app named “Sigmund” – created by a Harvard Ph.D student – is designed to program your dreams.

The app works this way: Before you go to bed, you choose from a list of about 1,000 words. The words come in a number of different categories, like “adventure,” “sports” and “romance.” The app calculates what time you’ll reach REM sleep, when you’re most likely to be dreaming, and then a soft, female voice repeats your selected words over your iPhone’s speaker.

The app is based on a study which suggested that it was possible to alter participants’ dreams about a third of the time.